What cpu mining Sapphire (SFRX), a subchain of Ethergem (EGEM), looks like on private testnet. The blockchain is being built from scratch by Osoese. One of the goals being a Dex able to transfer BTC at 5 seconds.
More Info here
https://egem.io/
and proof of 5 second testnet Bitcoin movement
https://bitcointalk.org/index.php?topic=5063954.msg50248883#msg50248883